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DebugIO

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Enjoy simplicity and flexibility

DebugIO is super simple. It is built on principle of recivers, who do all the stuff about sending logs somewhere.
DebugIO is super lightweight. It is just 260 lines of code.

Getting started

Simple logging

Let's start with a simple console logging:

const DebugIO = require("debugio");
const logger = new DebugIO({
  namespace: "example" // namespace of the logger, it has to be unique
});
logger.use(DebugIO.recivers.Console); // let's use default console logger
logger.log("hello world!"); // yay! it logs [example][log] hello world! 
logger.error("some error"); // oh... there is an error
logger.warn("wash your hands"); // and stay home as well

Recivers

Recivers are special functions, which handle logs. They accept following parameters:

logType: 'warn' | 'log' | 'error' - type of log
message: any - concatenated message
messages: any[] - splitted message
pretty: string - prettified message with main placeholder(check placeholders)

Here is an example of default Console reciver(ts syntax omitted):

const Console = (logType, message, messages, pretty) => {
  console[logType](pretty);
};

We can bind them to DebugIO instance using DebugIO.use()(like in the beginning) or passing them as recivers array in options

Inheritance

Second awesome part is instance inheritance. For example:

const test = new DebugIO({
  namespace: "test"
});

const test2 = new DebugIO({
  namespace: "test2",
  parent: test
});
test2.use(DebugIO.recivers.Console);

test2.log("inheritance test"); // [test][test2][log] inheritance test

As you see, we can add "sub-namespace" to existing namespace. Also, if a logger has a parent, we may not pass namespace, it will be omitted

Benchmarking

DebugIO has built-in method for benchmarking anything.

const test = new DebugIO({
  namespace: "test"
});
test.use(DebugIO.recivers.Console);
test.time("my super bench"); // create a label, which starts counting time since function execution
setTimeout(() => {
  test.timeEnd("my super bench"); // stop the label and output result with time placeholder
}, 1000);

Flexing the DebugIO

All possible options can be set up as static properties in DebugIO class.

Placeholders

In case you don't like standart way of prettifying strings, you can provide custom placeholders in DebugIO.placeholders field.
All place holders support the power of Handlebars

DebugIO.placeholders.namespace - default value is [{{namespace}}]. Used in prettifying namespaces. Available variables: namespace
DebugIO.placeholders.logType - default value is [{{rawLogType}}]. Used in prettifying log names. Available variables: rawLogType. Created for customizing log types
DebugIO.placeholders.main - default value is {{ prefix }}{{ namespaces }}{{ logType }} {{ pretty }}. Builds everything into one piece.
Variables:
- prefix - prefix you provided in DebugIO.prefix
- namespaces - namespaces chain built from namespace placeholder
- logType - logType from logType placeholder
- pretty - messages put into function joined by DebugIO.separator
DebugIO.placeholders.time - default value is {{label}}: {{time}}ms. Used in time and timeEnd functions(see benchmarking). Variables: time and label.

Providing custom template enigne

You can use your own template engine by providing DebugIO.render function. It'll accept those params: str - string to render; ctx - data to render. Default function:

import Handlebars from 'handlebars'
import TemplateEngine = require('./types/TemplateEngine');

const template: TemplateEngine = function (str: string, context: object): string {
  return Handlebars.compile(str)(context);
}

export = template;